1. Field of the Invention
The present invention relates to an apparatus for controlling a rate of flow of a liquid, having a conduit extending between a delivery site and a discharge site, and a flowmeter located in such conduit. The invention further relates to an application of the apparatus in a mixing plant which includes a plurality of such apparatuses.
2. Description of the Prior Art
In the field of controlling flow rates, may such be made by volumetric measuring apparatuses or also by rate flow measuring apparatuses, there always arises the problem regarding the reliability of the flow rate measuring apparatus, i.e. there always is the question of security regarding the value indicated by the flow rate meter and output therefrom for a further processing lying indeed within an allowable range of tolerance and being correct at all.
The apparatuses used until now solve this problem in part only because they are predominantly placed downstream of the flow rate controller and as a rule are not controlled or checked, respectively, by the respective process liquid but rather by water. Furthermore, the checking operation necessitates often an interruption of a production process and the flow rate meter is subjected only to a random controlling by an operator and usually only at the beginning of a production process.